Just based off the Roger vs Garp clash and how inferior it is compared to the Roger vs WB one in the Oden flashback, it’s very clear that these guys aren’t in their primes yet and still clearly getting stronger.
Rocks is older, more experienced and seems to be a lot stronger. I think God Valley will be where Garp/Roger will truly reach the top tier level kinda similar to how Luffy did on Onigashima. Their fame and also their power will bloom massively after GV.